Acemoglu and Robinson on Global Warming

I'm spending a large part of my day writing a book review of Daron Acemoglu and James A. Robinson's Why Nations Fail. Given the main theme of the book, which I like to focus on in reviews, I can't find a way to fit an interesting section they wrote on global warming. But it's important enough not to ignore. So here's the relevant excerpt, taken from a section sub-titled "The Long Summer":

About 15,000 BC, the Ice Age came to an end as the Earth's climate warmed up. Evidence from the Greenland ice cores suggests that average temperatures rose by as much as fifteen degrees Celsius in a short span of time. This warming seems to have coincided with rapid increases in human populations as the global warming led to expanding animal populations and much greater availability of wild plants and foods. This process was put into rapid reverse at about 14,000 BC, by a period of cooling known as the Younger Dryas, but after 9600 BC, global temperatures rose again, by seven degrees Celsius in less than a decade, and have since stayed high. Archaeologist Brian Fagan calls it the Long Summer. The warming-up of the climate was a huge critical juncture that formed the background to the Neolithic Revolution, where human societies made the transition to sedentary life, farming, and herding. This and the rest of subsequent human history have played out basking in this Long Summer.

That excerpt got me wondering: If this huge increase--15 degrees Celsius is 27 degrees Fahrenheit--was good for mankind, what degree of certainty can we put on the idea that another 2 or so degrees Celsius is really bad for mankind? I understand that you can't extrapolate and I understand that past some point, there's likely increasing marginal damage due to an extra degree. But a lot of damage? I'm skeptical.

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This is a good question. Part of the answer would be that we have built up our civilization to adapt to a certain temperature level, and so for that reason alone any change is likely to be costly.

For example, if we were starting civilization from scratch, it wouldn't really matter whether sea levels were 100 feet higher or 100 feet lower than they currently are. As it is, though, we've built many of our major cities near the current coastline, so that adapting to a big change in sea levels will be very costly.

A big temperature increase that gives your relatively small, not interconnected population more to hunt and gather seems like a different prospect than a more modest increase for several billion dependent on farther flung patterns of trade.

It's ultimately an unknown, and humans adapt, but there seems to be good reason for concern.

I agree with Blackadder, the adaptation to the temperature level is just one of the critical junctures A&R were talking about.
However, I don't see it all that important for explaining their crucial insights. They speak of many critical junctures. For me the bubonic plague was an interesting one in explaining the initial diversion between Western and Eastern Europe. But even more important than the historical events are the consequential effects and their role in institutional formation.

I wrote a review of the book for the Adam Smith Institute last year..
http://www.adamsmith.org/research/articles/review-why-nations-fail-the-origins-of-power-prosperity-and-poverty
...and my focus was on what I thought was their crucial insight - the role of extractivness and inclusivness of political institutions and their role in wealth creation and prosperity or wealth destruction and poverty. The critical junctures like the plague, the colonization patterns of North and South America, or the long summer are in my opinion just small pieces of the puzzle they use to reach their conclusions(like a control variable in an econometric model)

Another "2 degrees or so" almost certainly *isn't* on-net bad for humanity.

Even according to the IPCC, the next 1-3 degrees of warming is good for agricultural productivity - it'll be easier to feed the world. In the northern climates that are the most productive now, there will be longer growing seasons and more farmable area. In more equatorial regions, tree-farming will be more productive due to CO2 fertilization.

(1) Impacts are necessarily more difficult to predict than aggregate temperature increases, but what we can say is that something will change. If we don't know by how much, or how, by not preventing temperature increases we are taking on unknown risks. Do we really feel like gambling?

(2) Even if there is an aggregate benefit to humans, it is unlikely that rising temperatures will be good for everyone. The IPCC predicts that Africa will suffer serious consequences, for example. Africa's already got it pretty bad; do we want to make it worse? How can we adequately compensate Africans for rising temperatures largely caused by Western pollution?

(3) The IPCC has an entire section of their assessment report dedicated to the question of impacts, so rather than blindly speculating you could go see what actual climate scientists have to say.

I don't think the rise in sea level will be as expensive as everyone thinks. It won't happen overnight, and as old building get torn down, new ones will be built further inland. There will be a cost but its not like whole cities will be abandoned overnight.

I think the big difference is that we are a lot more efficient than before (which is why we can support 7 billion people) in a rising standard of living.

Unfortunately, efficiency is pretty much the opposite of robustness. There's no slack in the system to accommodate significant, non-local changes.

Jet engines are highly efficient, but if the world is throwing small rocks at my plane, I might well be better off with propellers.

While the USA is almost certainly going to directly survive the travails of almost any global scenario, it doesn't take a lot to imagine that global warming might imperil the government of a nation like India, and that such a government under threat might easily undertake risky actions against its usually enemies (like China) or, just possibly, upon those it perceives as responsible for its woes.

The problem is that in a nuclear-armed, financially-linked world, there really isn't a "somebody else's problem". A big enough hiccup *anywhere* can bring down the financial system, and the West has a *lot* more to lose.

The point I take from Acemoglu & Robinson is that agriculture and civilisation arose during a 12,000 year period of stable temperatures. Farmers have bred crops over many generations to maximise yields for that stable climate. Yields will probably drop after the change to a very different climate in the next century.

Also, the global temperature increase by 2100 is likely to be 2-3 degrees Celsius if CO2 emissions are rapidly reduced, but 4-6 degrees Celsius if CO2 emissions continue rising on their current trend.

Blackadder has the initial response correct. If climate change ends up being a problem, it will be due to the cost of adapting a society engineered for cooler temperatures.

But unless the changes in temperature are extreme, climate change is unlikely to have much impact either way. Human adaptability is so large and variable that the impacts of climate change will be lost in the noise. On the whole, small changes will likely be net positive, but hardly be noticed.

The most recent work suggests that large temperature changes (5 - 10 C) are extremely unlikely, less than previously thought. The most likely outcome for a doubling of CO2 appears to be

But unless the changes in temperature are extreme, climate change is unlikely to have much impact either way.

By "unlikely to have much impact", do you mean not much impact on humanity, or not much impact on highly industrialized, rich nations?

Not to pick on you, but I do find that "humanity = highly industrialized, rich nations" tends to be a pretty major part of the "global warming won't have much impact" mindset. It's worth remembering there are a few billion people who weren't born in the temperate zone.

No, I mean it will be especially inconsequential for the third world. My expectation is that, as we are seeing in China and India right now, wealth is going to grow dramatically over the next 50 years in countries that are currently poor. There's no reason why we can't effectively eradicate poverty around the world. Globalization will see to that. The increase in standard of living will be so large for the poor that no one will bother with concerns over climate change.

- shifts in consumer preferences due to rising incomes in developing countries and their convergence due to globalization, i.e. everyone on the planet would like to buy an iphone when given a chance... or increase their meat consumption... or etc.

@rapscallion: I may be misunderstanding your question, but whenever I hear the term "the long summer," it harks back to the late 1950s or early 1960s, to a Paul Newman movie, The Long, Hot Summer. I always figure it for a vague reference or joking pun re-using that time period or cultural reference in a different or lightly veiled way. Long before Game of Thrones (GOT)--if that's even what you are talking about.

If the costs of global warming for countries like India and China outweigh the costs of preventing it, then why are India and China two of the biggest opponents of international action on climate change?

It estimates that Africa's GDP will increase from $2T today to $29T by 2050. If GW's effect was HUGE and reduced Africa's future GDP to $15T, would anyone notice? I doubt it. They would just talk about how much wealthier Africa is, with 7x the GDP, and then wring their hands about overdevelopment and unsustainability.

If this huge increase ... was good for mankind, what degree of certainty can we put on the idea that another 2 or so degrees Celsius is really bad for mankind?

The hidden premise is that what's good or bad for mankind is what alarmists care about.

As for 'the long summer', I have also heard it used to describe the period just before the First Wolrd War, but I cannot remember where. (Tuchman?) But I wouldn't be surprised if that were an allusion to an earlier use of the phrase.

Mike Thicke (although he's not the only one) proposes the precautionary principle in his first bullet and then a series of negative possibilities that are pure speculation. Why not additional positive impacts?

(1) Warming temperatures increase rainfall over the Sahara turning the desert into grasslands or even tillable acreage supporting a newly prosperous continent.

(2) A northern trade route created because of an ice-free Arctic Ocean improves trade and raises the standard of living for billions of people.

(3) Migrations, and associated mixing of cultures, caused by coastal flooding result in less cultural conflict in the long term and lead to more trade, higher standard of living, and ultimately the survival of mankind.

The point I take from Acemoglu & Robinson is that agriculture and civilisation arose during a 12,000 year period of stable temperatures. Farmers have bred crops over many generations to maximise yields for that stable climate. Yields will probably drop after the change to a very different climate in the next century.

The "period of stable temperatures" is in comparison to the glacial period that occurs for roughly 80,000 years between "long summers", as well as the change during the "Younger Dryas" period. The drop in the Younger Dryas was 7 degrees in a decade vs NASA's estimate of 0.8 C in the past 130 years. Changes now are more comparable to the changes in the Medieval Warm period and the "little ice age" that we just came out of in the 1800s.

Edward again :

Also, the global temperature increase by 2100 is likely to be 2-3 degrees Celsius if CO2 emissions are rapidly reduced, but 4-6 degrees Celsius if CO2 emissions continue rising on their current trend.

Those predictions are becoming much less likely as time goes on. They were based on models that include high positive feedback via water vapor. It's not even clear whether such feedback is positive or negative.

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